Best RX satellite location ..

[LipolyGone]

My money is on the skookum as it wasnt replaced after its first crash but in light of what your saying about his 7hv having the odd little hiccup the week before who knows what it could be.

[Ross Northcott]

My money is on the skookum as it wasnt replaced after its first crash but in light of what your saying about his 7hv having the odd little hiccup the week before who knows what it could be.

Heathy found the problem was his 18mz at fault, he has now returned it to Futaba with a rather nasty cover letter, he said he has now bought a DX8 as he trusts this more and will be selling the 18mz,lol.

[jimmyhorns]

Heathy found the problem was his 18mz at fault, he has now returned it to Futaba with a rather nasty cover letter, he said he has now bought a DX8 as he trusts this more and will be selling the 18mz,lol.

Wind up merchant

[tomatwalden]

Wind up merchant

Who? Ross? No Jimmy, you don't know him.... he'd never say something contentious just for a laugh - not his style at all!

[Rob O]

Re: Best RX satellite location ..

HaHa thats the funniest thing you've ever said Ross
What with the DX8 being probably the most reliable radio ever made
Im jesting you know ,i,ve never had a problem with my old DX6i that i use for my b&f stuff . I picked the 8fg to go with my child size hands

[heathy]

Best RX satellite location ..

I've just replaced it with a dx4. Bloody futaba rubbish.

[tomatwalden]

I've just replaced it with a dx4. Bloody futaba rubbish.

LMAO!

[Ross Northcott]

I've just replaced it with a dx4. Bloody futaba rubbish.

Ha Ha lmao, sure you said replaced with a crash 8?

[cjcj1949]

It would be nice to have some rational technical tests done on the various systems. I was recently range testing my 130-x on DSM2 with my old DX7 and I could get 30metres at best and 10metres at worst depending on aerial orientation. 10 metres was pointing at the heli nose in. I doubt if the attenuation with a single aerial is that great as we aren't dealing with light but much longer wavelengths and there will be mutipath reception. It is mainly the in air reception that is of interest. I did notice that it did seem to take a while to reacquire on DSM2. Many things make a difference to how foolproof a system appears to be. A fast moving heli isn't in any orientation or position long enough for a brief loss of updates to cause a problem. I'm thinking of about 100ms for it to go from good to bad and back again.

Futaba do have a lot of experience and have designed their own chip. It is quite possible that they can increase the effective range by enough to make them appear very much better. It could also be that Futaba are more conservative, have better quality and more careful customers. They don't make a 130-X though. I just crashed mine when inverted, picked it up and it flew ok. Spectrum is bleeding edge and that's where you will get more innovation and more problems.

[xygax]

There is a specific difference between the standards of transmision. DSM2 uses 2 channels within the allocated band. DSMX uses 23 channels within the band and the futaba stansard uses them all. I have measured the relitive signal strengths in a chamber and they were basicly the same although the spektrum had some roll off at the upper end of the band probably caused by poor antanna matching it gets very critical in the centimeter bands.

The futaba standard is most likely a custom but the spektrum standard is specified as a 1Km range (one assumes perfect conditions for that) and is an amplified bluetooth standard (Cypress chipset) this does make it a bidirectional link by default (hence the telimetery )


Steve

[cjcj1949]

The range depends on how well the system is implemented and fundamentally the data rate used. The lower the data rate the greater the range for a given signal to noise ratio. With our needs we need very small amounts of data to get through rather than lots of data failing at maximum range. It is the failure condition that is important and how quickly we can recover from it. With analogue we had glitching servos when close to the limit, with digital we have perfect control and then nothing. Telemetry does give us signal quality feedback. I've found the telemetry on my Multiplex system very interesting. When doing range checks, passing lorries make a small difference. The maximum range will not be constant. It will vary as the noise level changes and what may be ok one day may not be ok on another.